The present invention relates to improvements in apparatus for manipulating rod-shaped articles, especially rod-shaped articles of the tobacco processing industry. More particularly, the invention relates to improvements in apparatus for changing the direction of transport of rod-shaped articles including plain or filter tipped cigarettes, cigars or cigarillos, filter rod sections and others. Still more particularly, the invention relates to improvements in apparatus for changing the direction of transport of articles which move axially so that the articles thereupon move sideways, i.e., at right angles to the respective axes.
A rod-making machine, such as a filter rod making machine, turns out a continuous rod wherein a rod-shaped filler of fibrous material is surrounded by a tubular wrapper consisting of cigarette paper, imitation cork or other suitable wrapping material. The leader of the rod is severed at regular intervals by the knife or knives of a suitable cutoff so that the severed articles form a single file of articles of unit length or multiple unit length. In order to further process such rod-shaped articles, it is often necessary to convert the single file into one or more rows wherein the articles are parallel to and are disposed one after the other, i.e., wherein the articles advance at right angles to their respective axes.
The conversion of a single file of coaxial rod-shaped articles, such as filter rod sections, cigarettes, cigars or cigarillos, into one or more rows presents serious problems in modern high-speed rod making machines which are designed to turn out large or extremely large quantities of rod-shaped articles per unit of time. The main problem is that the intervals of time which are available for effecting a change in the direction of movement of successive articles from axial movement in a file to sidewise movement in a row are extremely short (in the range of a few milliseconds) and the articles which have been caused to change the direction of their movement must be properly introduced into the receptacles (e.g., peripheral flutes) of a conveyor (such as a rapidly rotating drum) which serves to transport one or more rows of articles sideways. Improper operation of the direction changing mechanism or mechanisms can cause interruptions in the delivery of rod-shaped articles to the next processing machine (e.g., a filter tipping machine) and can also entail deformation of or even much more serious damage to (including total destruction of) the articles.
In order to facilitate the introduction of successive rod-shaped articles of a file of coaxial articles into successive peripheral flutes of a rotary drum-shaped conveyor, it is already known to accelerate successive articles by a rapidly rotating accelerating cam whose lobe or lobes engage and propel successive articles in a direction toward and into the oncoming flutes. Such cams are satisfactory as long as their peripheral speed is not very high; however, once the peripheral speed exceeds a certain value, the force with which the rapidly orbiting lobe or lobes strike relatively small portions of the wrappers of successive rod-shaped cigarettes, filter rod sections or like rod-shaped articles of the tobacco processing industry is so pronounced that the wrappers are scored or undergo other types of deformation or damage which renders them useless for further processing. It is to be borne in mind that a filter tipping machine must receive filter rod sections at a rate such that it can process the output of a cigarette maker which turns out up to and even in excess of 8000 plain cigarettes per minute.
It was further proposed to change the direction of movement of successive rod-shaped articles of a file of axially moving articles before the articles begin to enter the axially parallel flutes at the periphery of a rapidly rotating drum-shaped conveyor. In other words, each article of a file of such articles receives a component of movement in the circumferential direction of the drum even before the leaders of such articles enter the oncoming flutes. For example, German Pat. No. 1,228,978 discloses an apparatus wherein the discharge end of the conveyor which transports a single file of rod-shaped articles is adjacent to a driven wheel whose axis is slightly inclined with reference to the axes of the oncoming articles of the file and which has a helical peripheral flute serving to impart to successive articles a component of movement at right angles to the longitudinal directions of the peripheral flutes of the drum-shaped conveyor whereon the single file of articles (namely cigarettes) is converted into one or more rows. The surface bounding the helical groove in the peripheral surface of the wheel is formed with suction ports which are connected to a suction generating device so that the wheel attracts the articles which reach the discharge end of the conveyor for the single file of such articles. The peripheral speed of the wheel is selected in such a way that successive articles of the file are accelerated in the axial direction as well as in the circumferential direction of the fluted drum. A drawback of the patented apparatus is that the wheel attracts only very short portions of the wrappers of successive cigarettes, and more particularly very short portions of the wrappers at the leading ends of successive articles. Therefore, the change in the direction of transport of successive cigarettes is so abrupt that the articles change their orientation and cannot readily enter the oncoming flutes. Such apparatus might be satisfactory when the cigarettes of the single file are delivered at a relatively low speed but it is incapable of properly introducing successive cigarettes or like rod-shaped articles of the tobacco processing industry into successive flutes of a rotating drum as soon as the speed of the drum exceeds a certain value which is well below that required in a modern filter tipping or like machine. It has been found that, when the speed of axial movement of the cigarettes which form the single file is relatively high, the wheel with its helical groove and suction ports in the surface bounding the helical groove cannot adequately control the movements of the cigarettes and also that the cigarettes are subjected to excessive and hence totally unacceptable bending and buckling stresses. Therefore, the patented apparatus is not suited for the transfer of, for example, filter rod sections into successive flutes of a rotating drum in a modern filter tipping machine.
German Offenlegungsschrift No. 27 49 225 discloses a modified apparatus wherein successive rod-shaped articles of the single file are also caused to change the direction of their movement even before they enter the peripheral flutes of a rotary drum-shaped conveyor for one or more rows of such rod-shaped articles. This German printed publication discloses a foraminous belt conveyor one side of which is adjacent to a suction chamber and the other side of which transports successive articles of the single file into the range of two discs each of which has a lobe with an arcuate article-engaging surface of gradually increasing radius. The conveyor accelerates the articles of the file axially and the lobes of the two discs push the oncoming articles sideways so that the articles are shifted along the foraminous conveyor in the circumferential direction of the row-forming drum. The speeds of the discs and the configurations of their lobes are selected in such a way that successive articles of the file are accelerated to the peripheral speed of the drum before their leaders enter the oncoming axially parallel peripheral flutes of the drum. It has been found that the just described prior apparatus treats the articles rather gently, when compared with the treatment by the aforementioned wheel with its helical groove, but that the mechanical stressing of the articles is still excessive when the articles are to be fed into a modern filter tipping machine or the like. This is due to the fact that, on the one hand, the articles are caused to adhere to the foraminous conveyor opposite to the suction chamber and, on the other hand, the lobes of the discs cause the articles to move along the conveyor sideways and to rapidly acquire a component of movement in the peripheral direction of the drum so that their speed in such peripheral direction matches the peripheral speed of the drum at the instant of entry of their leaders into the oncoming axially parallel flutes. In addition, the apparatus must employ discrete drive means for the foraminous conveyor and for the discs. This contributes to the bulk, initial cost, maintenance cost and proneness to malfunction of such apparatus.